Cortical stimulation of language fields under local anesthesia: optimizing removal of brain lesions adjacent to speech areas

Abstract

-Objective: The main objective when resecting benign brain lesions is to minimize risk of postoperative neurological deficits. We have assessed the safety and effectiveness of craniotomy under local anesthesia and monitored conscious sedation for the resection of lesions involving eloquent language cortex. Method: A retrospective review was performed on a consecutive series of 12 patients who underwent craniotomy under local anesthesia between 2001 and 2004. All patients had lesions close to the speech cortex. All resection was verified by post-operative imaging. Six subjects were male and 6 female, and were aged between 14 and 52 years. Results: Lesions comprised 7 tumour lesions, 3 cavernomas and 1 dermoid cyst. Radiological gross total resection was achieved in 66% of patients while remaining cases had greater than 80% resection. Only one patient had a post-operative permanent deficit, whilst another had a transient post-operative deficit. All patients with uncontrollable epilepsy had good outcomes after surgery. None of our cases subsequently needed to be put under general anesthesia. Conclusion: Awake craniotomy with brain mapping is a safe technique and the "gold standard" for resection of lesions involving language areas.Key WORdS: cortical mapping, awake craniotomy, tumor, speech area. mapeamento cortical da fala com o paciente acordado: optimização para ressecção de lesões intracranianas localizadas próximas à área da falaResumo -Objetivo: O presente estudo visa discutir as vantagens e as limitacões do uso da técnica de mapeamento cortical da área da fala com o paciente acordado. Método: esta é uma revisão retrospectiva dos casos em que foi realizado monitoramento cortical intraoperatório em cirurgias para ressecção de lesões intracranianas localizadas próximas à área da fala. Todos os pacientes foram submetidos a avaliação neuropsicológica no pré e intra-operatório. O grau das ressecções foi verificado através de exames de imagem pós-operatórios. Foram avaliados um total de 12 pacientes. destes, 6 eram do sexo masculino e 6 do feminino. Resultados: 7 lesões eram tumorais. A ressecção total foi atingida em 66% e ressecção subtotal nos remanescentes. Apenas 1 paciente apresentou déficit motor permanente no pós-operatório e todos os pacientes com quadro prévio de epilepsia refratária obtiveram bom controle das crises no pós-operatório. em nenhum caso houve necessidade de conversão da anestesia para geral. Conclusão: O mapeamento funcional intraoperatório na craniotomia com o paciente acordado otimiza a extensão da ressecção da lesão minimizando morbidade permanente. esta é uma técnica eficaz no manejo de lesões em íntimo contato com o córtex eloqüente, que outrora, seriam designadas inoperáveis.

Awake Mapping Optimizes the Extent of Resection for Low-Grade Gliomas in Eloquent Areas

“…[27][28][29][30][31][32][33][34][35][36][37][38][39][40] Advances in methods of intraoperative functional mapping in awake patients have been demonstrated to significantly increase indications of surgical resection while minimizing the risk of permanent deficit for low-grade gliomas located within the so-called eloquent areas, classically considered inoperable. 2,11,[41][42][43][44][45][46][47][48][49][50] Here, we reviewed the recent literature from 2003 on surgery for gliomas in functional regions (Table 4). It shows that the use of intraoperative electrical mapping has decreased the incidence of permanent neurological deficit to 4.1% (analysis of 1460 surgical resections for glioma, including 522 low-grade gliomas).…”

“…However, no extensive functional assessment was performed after the first surgery, especially concerning language. Postoperative MRI revealed www.neurosurgery-online.com (50); the head of the caudate nucleus superiorly, generating perseverations when stimulated (49); and the descending fibers from the ventral premotor cortex, where stimulation generated articulatory disturbances (45 . Histological examination revealed a World Health Organization (WHO) grade II glioma in 8 patients and a WHO grade I glioma in 1 patient (ganglioglioma).…”

Resection frequency map after awake resective surgery for non-lesional neocortical epilepsy involving eloquent areas

“…A few reports describe the resection of the Broca’s area with definite lesion (e.g. brain tumour) [5, 13]. In the present study, two patients in the cohort underwent resection of the pars triangularis of the dominant hemisphere as a part of the Broca’s area (cases 19 and 21 in Table 5), which can be delineated using anatomical and MRI landmarks [38], and six patients that of its adjacent cortex (cases 11, 18, 20, 22, 23, and 24 in Table 5).…”

Use of intraoperative MRI for resection of gliomas

“…When necessary, motor areas were mapped before surgery with transcranial magnetic stimulation (TMS) or during the procedure with electrical stimulation, as reported before 19 . Unfortunately, language areas could not be mapped during surgeries using intra-operative MRI.…”